Time Dependence of Risks and Benefits in Pediatric Primary Prevention Implantable Cardioverter-Defibrillator Therapy

Abstract

Background-Implantable cardioverter defibrillators (ICDs) used to prevent sudden cardiac arrest in children not only provide appropriate therapy in 25% of patients but also result in a significant incidence of inappropriate shocks and other device complications. ICDs placed for secondary prevention have higher rates of appropriate therapy than those placed for primary prevention. Pediatric patients with primary prevention ICDs were studied to determine time-dependent incidence of appropriate use and adverse events. Methods and Results-A total of 140 patients aged <21 years (median age, 15 years) at first ICD implantation at BostonChildren 's Hospital (2000's Hospital ( -2009 in whom devices were placed for primary prevention were retrospectively identified. Demographics and times to first appropriate shock; adverse events (including inappropriate shock, lead failure, reintervention, and complication); generator replacement and follow-up were noted. During mean follow-up of 4 years, appropriate shock occurred in 19% patients and first adverse event (excluding death/transplant) occurred in 36%. Risk of death or transplant was ≈1% per year and was not related to receiving appropriate therapy. Conditional survival analysis showed rates of appropriate therapy and adverse events decrease soon after implantation, but adverse events are more frequent than appropriate therapy throughout follow-up. Conclusions-Primary prevention ICDs were associated with appropriate therapy in 19% and adverse event in 36% in this cohort. The incidence of both first appropriate therapy and device-related adverse events decreased during longer periods of follow-up after implantation. This suggests that indications for continued device therapy in pediatric primary prevention ICD patients might be reconsidered after a period of nonuse. (Circ Arrhythm Electrophysiol.

Implantable Cardioverter Defibrillator Outcomes in Pediatric and Congenital Heart Disease: Time to System Revision

“…Most studies on ICD complications in pediatric and CHD patients assess all complications and typically highlight inappropriate shocks or other complications such as infection . A recent study shows that 26% of pediatric patients with primary prevention ICDs required reintervention but did not elaborate on indication or timing . System revision is a major complication of ICD implantation, as it requires a surgical procedure which imposes morbidity and increases the risk of mortality.…”

“…Despite the life‐saving potential of ICDs, they may impose significant morbidity. Device complications occur in up to 32% of pediatric and congenital heart disease (CHD) patients . A recent study of primary prevention ICDs in this population showed that the risk of complication was greater than the risk of receiving an appropriate shock …”

Sudden Cardiac Death in the Young

“…From the point of view of risk of ICD, children clearly have a relatively high rate of complications associated with devices, including frequency of inappropriate shocks, lead malfunctions and difficulties in ICD placement related to intracardiac anatomy and small size. 152, 153 Conversely, from the point of view of potential benefits associated with primary prophylaxis, children may stand to gain relatively less from ICD implantation. In particular, the known rate of sudden death associated with congenital heart disease and a variety of arrhythmic cardiomyopathies is considerably lower than that observed in adult populations in whom ICD is seen to be useful (e.g., as mentioned above for adults tetralogy of Fallot, in whom these rates range from 0.1 – 0.2%/yr).…”

Decreased inappropriate shocks with new generation ICDs in children and patients with congenital heart disease

“…The rate of inappropriate shocks from all devices in our study was 4.1 per 100 device-years, within the range previously reported for children and patients with CHD: 3.5-9.8 per 100 device years. [1][2][3][4]24 When isolating the new generation devices, however, the incidence of inappropriate shocks was much lower: 6.3% over 4 years follow-up, or 1.3 per 100 device-years.…”